1. Field
Aspects of the present disclosure relate generally to touch sensor systems, and more particularly, to a method and apparatus for biometric-based security using capacitive profiles.
2. Background
Biometrics-based security offers convenience for users because there is nothing to be remembered and nothing to lose. Thus, a user may be authenticated or identified based on one or more biometrics belonging to the user. For example, a biometric authentication approach utilizes physical characteristics of a user's anatomy, such as handprints or fingerprints, for authenticating the user. As another example, a biometric authentication approach utilizes face recognition and voice recognition systems for authentication the user. The approaches provided in the latter example are convenient because they do not depend on the user physically touching the security system for identification. However, they are extremely susceptible to environmental parameters in which these systems operate, including insufficient lighting or excessive background noise. Further, for an audio-based biometric security system such as the aforementioned voice recognition system, limitations on deployment may include quiet environments that are optimized for capturing a user's voice clearly, but ironically that are intolerant of audio disturbances. These include such environments as occupied movie theaters, conference rooms, classrooms, and libraries. Many of these aforementioned issues are exacerbated for biometric security systems utilizing mobile devices because there is often very little predictability of or control over the environments in which mobile devices will operate.
Examples of biometric sensing schemes that are typically used for biometric security systems on mobile devices include physical sensing schemes and optical read schemes. In an optically based read scheme, a picture of a body part is captured as optical image data using mainly light reflection and an image sensor. In contrast, in a physically based sensing scheme, effects of a body part on sensors such as capacitive sensors are determined Typically, these sensors are formed into an array, with a sensing resolution that depends on how densely the sensors need to be packed in the array. For example, fingerprint authentication is commonly used as a biometric authentication method, but users may not accept this approach because of its association with criminality and privacy concerns, such as where a governmental database could be linked to identify the fingerprints. In addition, the fingerprint authentication approach typically involves increased hardware implementation costs due to a need to employ high-resolution sensors to be able to accurately read fingerprints. These high-resolution sensors are typically separated from other touch-sensing devices such as touchscreens. The “Touch ID” fingerprint authentication system used in the iPhone® 5s from Apple, Inc. and the “Fingerprint Scanner” fingerprint authentication system used in the Galaxy® S5 from Samsung Electronics Co., Ltd. are examples of these high-resolution sensors.
In contrast to specialized sensor devices such as the aforementioned fingerprint sensors, touchscreens are commonly found in a variety of devices in today's industrial and consumer markets including such devices as cellular phones, global positioning (GPS) devices, set-top boxes, still and video cameras, computer screens, digital audio players, digital tablets, and the like. Because of their ubiquity and widespread implementation, touchscreens may be utilized to create biometric authentication systems that may be less costly and complex to implement as compared to those using specialized, high-resolution types of sensors such as, for example, fingerprint sensors. In many instances, biometric security systems that utilize touchscreens would not require additional hardware.
For example, one type of touchscreen-based biometric system that is generally referred to as a behavioral biometric system uses touchscreen behavior to verify users from common touchscreen gestures, such as scroll, pinch and tap. Some behavioral biometric systems have extended this further to use parameters such as dwell-time and touch pressure to enhance user authentication. However, behavioral biometric systems are time-based in that, inherently, they can only provide authentication of a user after the user has utilized the system for a required period of time. Further, behavioral biometric systems are generally not as accurate as another type of touchscreen-based biometric system referred to generally as a physical biometric system that utilizes physical biometric characteristics to verify users system.
It would be desirable for a biometrics-based security solution to be low cost, offer convenience, provide accuracy, and utilize existing hardware while offering simple user interaction.